The primary objective of the study will be to compare the changes in renal plasma flow following the oral administration of Irbesartan to salt restricted Caucasian, Hispanic, and African American subjects with nephropathy due to Type II diabetes mellitus. The secondary objectives of the study will be to ascertain the safety and tolerability of a single dose administration of the drug and to compare the changes in Glomerular filtration rate, filtration fraction, and the renin angiotensin system components following the administration of the optimal dose of Irbesartan in salt restricted subjects with nephropathy due to Type II diabetes mellitus.